JPS6056197B2 - hot melt adhesive composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hot melt adhesive composition.

Many hot-melt adhesives made from thermoplastic resins such as polyethylene, ethylene-vinyl acetate copolymers, ionomers, and nylon have been known.

However, polyethylene, ethylene vinyl acetate copolymer,
When ionomers and the like are used for adhering metals, etc., sufficient adhesion strength cannot be obtained, making it difficult to put them into practical use.

Also, although nylon has a certain degree of adhesive strength to metals, it is not yet sufficient, so nylon is mixed with epoxy resin, or so-called nylon-epoxy adhesives, which are coated with epoxy resin on both sides of a nylon film, are used. Hot-melt adhesives have been proposed, but such adhesives require a considerable amount of time to complete curing and are expensive, so they are not suitable for general use. It is not suitable as a temporary adhesive. Also, ethylene on nylon
Attempts have been made to improve adhesive strength by mixing vinyl acetate copolymers, ionomers, etc., but in none of these cases has a satisfactory result been achieved in improving adhesive strength. Improvement in strength is desired. In view of the current situation, the present invention has been made for the purpose of providing a hot melt adhesive composition that has excellent adhesive strength to metals, etc., is easy to use, and is inexpensive. A hot melt adhesive composition characterized in that 1 to 20 parts by weight of a vinyl aromatic hydrocarbon polymer is mixed with 100 parts by weight. In the present invention, the nylon polymer is generally referred to as nylon, and includes nylon 12, nylon 11, nylon 6, nylon 66, nylon 610, etc., which are conventionally known to be used as hot melt adhesives. It refers to a copolymer.

In addition, the polymer of vinyl aromatic hydrocarbon refers to a homopolymer of a polymerizable vinyl aromatic hydrocarbon monomer, or a polymer of other polymerizable monomers mainly composed of the vinyl aromatic hydrocarbon monomer. refers to a copolymer of

In the present invention, homopolymers or copolymers of vinyl aromatic hydrocarbons having 8 to 20 carbon atoms, such as polystyrene, polyα-methylstyrene, polyvinyltoluene,
Polyβ-methylstyrene, polytert-butylstyrene, polyisopropenyltoluene, etc. are preferably used, and polystyrene is particularly preferably used. To produce the adhesive composition of the present invention, the nylon polymer and the vinyl aromatic hydrocarbon polymer may be added and mixed to form an appropriate shape. Mix powder or pellets and use an extruder to form them into a film, line, or pellet, or roll,
A method of kneading with a kneader, Panbury mixer, etc. and forming it into a sheet shape or the like can be suitably employed.

As for the amounts of the nylon polymer and the vinyl aromatic hydrocarbon polymer, it is necessary to use the latter in a range of 1 to 20 parts by weight per 10 parts by weight of the former. The reason for this is that if the amount of the vinyl aromatic hydrocarbon polymer used is less than 1 part by weight, the effect of increasing the peel strength of the resulting adhesive composition will not be achieved, and if it exceeds 20 parts by weight, This is presumably because the limit of miscibility with the nylon polymer is exceeded, but the peel strength tends to decrease.

The adhesive composition of the present invention can be used for the same purposes as general hot-melt adhesives, but in particular metal materials such as iron, aluminum, copper, and brass, glass, ceramics, etc.
It exhibits excellent properties when used to bond inorganic materials such as slate and concrete, fibrous materials such as cotton, silk, wool, Tetoron, nylon, and fibers, and paper products.

Note that additives such as colorants and fillers may be added to the adhesive composition of the present invention as necessary. Since the hot melt adhesive composition of the present invention has the above-described structure, it can exhibit excellent adhesive strength.

Examples of the present invention will be described below.

Examples 1-2 Copolymerized nylon (melting point 117°C, melt index 3
5) and polystyrene (Viscut softening point: 85° C., melt index: 27) in the proportions shown in Table 1, and extruded into a film with a thickness of 100 microns using an extruder to obtain a film adhesive.

Next, this adhesive was greased with acetone to a thickness of 0.6TIr1.
Placed between two 1t galvanized steel plates, the steel plates were bonded together at a temperature of 120°C and a pressure of 2K9/C7lf for 2 minutes. After bonding, the steel plates were left for 3 days at 2CfC and a relative humidity of 60%. did.

The T-peel strength of the thus bonded galvanized steel sheets was measured.

The measurement conditions were a peeling rate of 50 Wfi/min, a sample width of 25 pieces, a temperature of 20° C., and a humidity of 60%. Table 1 shows the measurement results of T peel strength. Examples 3-4 Nylon 12 (melting point 179, cutt softening point 85°C, melt index 27) was used as the first
An adhesive was prepared in the same manner as in Example 1 by blending in the proportions shown in the table.

Next, a sample was prepared in the same manner as in Example 1 except that bonding was performed at a temperature of 240° C. and a pressure of 2K9/Criel for 2 minutes, and the T-peel strength was measured. The results were as shown in Table 1. Comparative Example 1 An adhesive was prepared in the same manner as in Example 1 using only copolymerized nylon (same as in Example 1), and the T-peel strength was measured.

The results were as shown in Table 1.

Comparative Example 2 The same procedure as in Example 5 was carried out except that nylon 12 (same as in Example 3) was used alone as an adhesive.

The results were as shown in Table 2. Examples 5 to 8, Comparative Examples 3 to 4 In the same manner as in Example 1, adhesives having the compositions shown in Tables 2 and 3 were prepared, and the T-peel strength was measured.

The results were as shown in the table. The same copolymerized nylon and polystyrene as in Example 1 were used, and the same as in Example 3 was used as nylon 12.

Claims (1)

Claims: 1. A hot melt adhesive composition comprising 1 to 200 parts by weight of a vinyl aromatic hydrocarbon polymer mixed with 100 parts by weight of a nylon polymer. 2. The composition according to item 1, wherein the vinyl aromatic hydrocarbon polymer is polystyrene.